replaced not with now

Author: OlivierJM

responses/11.0_add-descriptions.md

@@ -1,5 +1,5 @@
 ### Course metadata
-Remember your course's metadata, near the top of your config? We left the description and tagline empty at the start of this course, but it's not time to fill them in.
+Remember your course's metadata, near the top of your config? We left the description and tagline empty at the start of this course, but it's now time to fill them in.
 
 The [:book: course description and tagline](https://lab.github.com/docs/3-4-yaml#relevant-syntax) will be included on the Learning Lab site. Users will see this information before they sign up for the course.